An Optimized Hybrid SOVM Modulation Based on MDAVT for OEWIM

Abstract

This paper presents a new optimized hybrid space opposite vectors modulation (SOVM) strategy based on the multiple division of active vector time (MDAVT) for a dual inverter fed open end winding induction motor (OEWIM) to reduce the common mode voltage (CMV) as well as line current harmonic distortion. Ordinarily, to drive all ac drives at variable voltage and frequencies voltage source inverters (VSIs) need to be employed. In this regard various PWM strategies came into existence to provide gating signals to VSIs. Mostly all the PWM converters yields CMV across the load terminals which in turn results common mode currents. These common mode currents lead to the electromagnetic interference and explicitly responsible for the failure of bearings in case of motor loads. In order to reduce this CMV in this paper, a SOVM strategy is adapted. The concept of an optimized MDAVT is also introduced along with the SOVM to obtain the less current ripple. Finally these adaptions lead to an optimized hybrid PWM strategy and is employed for dual two level inverter fed OEWIM. In the present work in order to evaluate the optimistic performance of proposed switching strategy for OEWIM MATLAB software is chosen. And to validate the proposed strategy experimentally dSPACE 1104 is employed for digital implementation of PWM signals. Finally the superiority of the proposed PWM scheme in terms of CMV is presented with the detailed analysis. Whereas, the superiority in terms of current THD is shown with the help of the simulation and experimental results.